Positive surgical margins after partial nephrectomy across changing surgical eras: long-term oncological results from a tertiary referral center.

purposeto reassess the prognostic value of positive surgical margins (PSM) after partial nephrectomy (PN) in terms of relapse-free survival (RFS), progression-free survival (PFS), overall survival (OS) and cancer-specific mortality (CSM) within a large cohort spanning changing surgical eras, including the progressive adoption of minimally invasive approaches. MATERIALS AND

methodsWe retrospectively analyzed 1441 patients who underwent PN for cM0 renal tumors between 2000 and 2024 at a tertiary referral center. Patients were stratified according to margin status (PSM vs. negative surgical margins, NSM). Kaplan-Meier analyses estimated RFS, PFS, and OS, while uni (UVA)- and multivariable (MVA) Cox regression models stratified by surgical era (2000-2011 vs. 2012-2024) tested the association between PSM and local relapse, progression, and all-cause mortality. Fine-Gray regression tested PSM impact on CSM. Then, exploratory interaction and subgroup analyses according to surgical approach were also performed.

resultsOf 1441 included patients, 81 (5.6%) had PSM on final pathology. Apart from a higher proportion of females in the PSM group (42% vs. 31%, p = 0.03), no clinical or pathological differences were observed between PSM and NSM (all p > 0.1). At 5-year follow-up, RFS, PFS, and OS were 90.5% vs. 96.7% (p = 0.003), 94.9% vs. 94.4% (p = 0.7), and 91.3% versus 94.4% (p = 0.1) for PSM vs. NSM, respectively. After adjustment for the selected clinical variables, PSM were associated with higher hazard of local relapse (HR: 4.03, 95% CI: 1.64-9.87; p = 0.002). No statistically significant association was observed between PSM and systemic progression (HR: 1.15, 95% CI: 0.35-3.74; p = 0.8), all-cause mortality (HR: 1.96, 95% CI: 0.82-4.72; p = 0.1), or CSM on Fine-Gray analysis (SHR: 2.66, 95% CI: 0.58-12.1, p = 0.2). However, the number of progression and mortality events in the PSM group was limited, resulting in wide CIs.

conclusionsPSM after PN were independently associated with a higher risk of local recurrence. No statistically significant association was observed with systemic progression, CSM, or OS; however, these analyses were limited by the small number of events, and clinically meaningful effects cannot be excluded. These findings support careful postoperative surveillance while larger contemporary studies are needed to better define the long-term prognostic impact of PSM.